The image shows the chemical structural formulas of different hemoglobin structures. Hemoglobin is the ferrous blood pigment in the erythrocytes and its variation. It enables the transport of oxygen trough the body. Depending on its loading with oxygen, hemoglobin has two forms: Oxygenated oxyhemoglobin and desoxygenated desoxyhemoglobin. Carbamino hemoglobin is loaded with carbon dioxide.